using System;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;
using System.util.zlib;
/*
 * Copyright 2003 by Paulo Soares.
 *
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (the "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the License.
 *
 * The Original Code is 'iText, a free JAVA-PDF library'.
 *
 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
 * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
 * All Rights Reserved.
 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
 * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
 *
 * Contributor(s): all the names of the contributors are added in the source code
 * where applicable.
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
 * provisions of LGPL are applicable instead of those above.  If you wish to
 * allow use of your version of this file only under the terms of the LGPL
 * License and not to allow others to use your version of this file under
 * the MPL, indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by the LGPL.
 * If you do not delete the provisions above, a recipient may use your version
 * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the MPL as stated above or under the terms of the GNU
 * Library General Public License as published by the Free Software Foundation;
 * either version 2 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
 * details.
 *
 * If you didn't download this code from the following link, you should check if
 * you aren't using an obsolete version:
 * http://www.lowagie.com/iText/
 */

namespace iTextSharp.text.pdf.codec {
    /** Reads TIFF images
    * @author Paulo Soares (psoares@consiste.pt)
    */
    public class TiffImage {
        
        /** Gets the number of pages the TIFF document has.
        * @param s the file source
        * @return the number of pages
        */    
        public static int GetNumberOfPages(RandomAccessFileOrArray s) {
            return TIFFDirectory.GetNumDirectories(s);
        }

        static int GetDpi(TIFFField fd, int resolutionUnit) {
            if (fd == null)
                return 0;
            long[] res = fd.GetAsRational(0);
            float frac = (float)res[0] / (float)res[1];
            int dpi = 0;
            switch (resolutionUnit) {
                case TIFFConstants.RESUNIT_INCH:
                case TIFFConstants.RESUNIT_NONE:
                    dpi = (int)(frac + 0.5);
                    break;
                case TIFFConstants.RESUNIT_CENTIMETER:
                    dpi = (int)(frac * 2.54 + 0.5);
                    break;
            }
            return dpi;
        }
        
        /** Reads a page from a TIFF image. Direct mode is not used.
        * @param s the file source
        * @param page the page to get. The first page is 1
        * @return the <CODE>Image</CODE>
        */    
        public static Image GetTiffImage(RandomAccessFileOrArray s, int page) {
            return GetTiffImage(s, page, false);
        }
        
        /** Reads a page from a TIFF image.
        * @param s the file source
        * @param page the page to get. The first page is 1
        * @param direct for single strip, CCITT images, generate the image
        * by direct byte copying. It's faster but may not work
        * every time
        * @return the <CODE>Image</CODE>
        */    
        public static Image GetTiffImage(RandomAccessFileOrArray s, int page, bool direct) {
            if (page < 1)
                throw new ArgumentException("The page number must be >= 1.");
            TIFFDirectory dir = new TIFFDirectory(s, page - 1);
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_TILEWIDTH))
                throw new ArgumentException("Tiles are not supported.");
            int compression = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_COMPRESSION);
            switch (compression) {
                case TIFFConstants.COMPRESSION_CCITTRLEW:
                case TIFFConstants.COMPRESSION_CCITTRLE:
                case TIFFConstants.COMPRESSION_CCITTFAX3:
                case TIFFConstants.COMPRESSION_CCITTFAX4:
                    break;
                default:
                    return GetTiffImageColor(dir, s);
            }
            float rotation = 0;
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_ORIENTATION)) {
                int rot = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_ORIENTATION);
                if (rot == TIFFConstants.ORIENTATION_BOTRIGHT || rot == TIFFConstants.ORIENTATION_BOTLEFT)
                    rotation = (float)Math.PI;
                else if (rot == TIFFConstants.ORIENTATION_LEFTTOP || rot == TIFFConstants.ORIENTATION_LEFTBOT)
                    rotation = (float)(Math.PI / 2.0);
                else if (rot == TIFFConstants.ORIENTATION_RIGHTTOP || rot == TIFFConstants.ORIENTATION_RIGHTBOT)
                    rotation = -(float)(Math.PI / 2.0);
            }

            Image img = null;
            long tiffT4Options = 0;
            long tiffT6Options = 0;
            int fillOrder = 1;
            int h = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_IMAGELENGTH);
            int w = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_IMAGEWIDTH);
            int dpiX = 0;
            int dpiY = 0;
            float XYRatio = 0;
            int resolutionUnit = TIFFConstants.RESUNIT_INCH;
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_RESOLUTIONUNIT))
                resolutionUnit = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_RESOLUTIONUNIT);
            dpiX = GetDpi(dir.GetField(TIFFConstants.TIFFTAG_XRESOLUTION), resolutionUnit);
            dpiY = GetDpi(dir.GetField(TIFFConstants.TIFFTAG_YRESOLUTION), resolutionUnit);
            if (resolutionUnit == TIFFConstants.RESUNIT_NONE) {
                if (dpiY != 0)
                    XYRatio = (float)dpiX / (float)dpiY;
                dpiX = 0;
                dpiY = 0;
            }
            int rowsStrip = h;
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_ROWSPERSTRIP))
                rowsStrip = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_ROWSPERSTRIP);
            if (rowsStrip <= 0 || rowsStrip > h)
                rowsStrip = h;
            long[] offset = GetArrayLongShort(dir, TIFFConstants.TIFFTAG_STRIPOFFSETS);
            long[] size = GetArrayLongShort(dir, TIFFConstants.TIFFTAG_STRIPBYTECOUNTS);
            if ((size == null || (size.Length == 1 && (size[0] == 0 || size[0] + offset[0] > s.Length))) && h == rowsStrip) { // some TIFF producers are really lousy, so...
                size = new long[]{s.Length - (int)offset[0]};
            }
            bool reverse = false;
            TIFFField fillOrderField =  dir.GetField(TIFFConstants.TIFFTAG_FILLORDER);
            if (fillOrderField != null)
                fillOrder = fillOrderField.GetAsInt(0);
            reverse = (fillOrder == TIFFConstants.FILLORDER_LSB2MSB);
            int paramsn = 0;
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_PHOTOMETRIC)) {
                long photo = dir.GetFieldAsLong(TIFFConstants.TIFFTAG_PHOTOMETRIC);
                if (photo == TIFFConstants.PHOTOMETRIC_MINISBLACK)
                    paramsn |= Image.CCITT_BLACKIS1;
            }
            int imagecomp = 0;
            switch (compression) {
                case TIFFConstants.COMPRESSION_CCITTRLEW:
                case TIFFConstants.COMPRESSION_CCITTRLE:
                    imagecomp = Image.CCITTG3_1D;
                    paramsn |= Image.CCITT_ENCODEDBYTEALIGN | Image.CCITT_ENDOFBLOCK;
                    break;
                case TIFFConstants.COMPRESSION_CCITTFAX3:
                    imagecomp = Image.CCITTG3_1D;
                    paramsn |= Image.CCITT_ENDOFLINE | Image.CCITT_ENDOFBLOCK;
                    TIFFField t4OptionsField = dir.GetField(TIFFConstants.TIFFTAG_GROUP3OPTIONS);
                    if (t4OptionsField != null) {
                        tiffT4Options = t4OptionsField.GetAsLong(0);
                    if ((tiffT4Options & TIFFConstants.GROUP3OPT_2DENCODING) != 0)
                        imagecomp = Image.CCITTG3_2D;
                    if ((tiffT4Options & TIFFConstants.GROUP3OPT_FILLBITS) != 0)
                        paramsn |= Image.CCITT_ENCODEDBYTEALIGN;
                    }
                    break;
                case TIFFConstants.COMPRESSION_CCITTFAX4:
                    imagecomp = Image.CCITTG4;
                    TIFFField t6OptionsField = dir.GetField(TIFFConstants.TIFFTAG_GROUP4OPTIONS);
                    if (t6OptionsField != null)
                        tiffT6Options = t6OptionsField.GetAsLong(0);
                    break;
            }
            if (direct && rowsStrip == h) { //single strip, direct
                byte[] im = new byte[(int)size[0]];
                s.Seek(offset[0]);
                s.ReadFully(im);
                img = Image.GetInstance(w, h, false, imagecomp, paramsn, im);
                img.Inverted = true;
            }
            else {
                int rowsLeft = h;
                CCITTG4Encoder g4 = new CCITTG4Encoder(w);
                for (int k = 0; k < offset.Length; ++k) {
                    byte[] im = new byte[(int)size[k]];
                    s.Seek(offset[k]);
                    s.ReadFully(im);
                    int height = Math.Min(rowsStrip, rowsLeft);
                    TIFFFaxDecoder decoder = new TIFFFaxDecoder(fillOrder, w, height);
                    byte[] outBuf = new byte[(w + 7) / 8 * height];
                    switch (compression) {
                        case TIFFConstants.COMPRESSION_CCITTRLEW:
                        case TIFFConstants.COMPRESSION_CCITTRLE:
                            decoder.Decode1D(outBuf, im, 0, height);
                            g4.Fax4Encode(outBuf, height);
                            break;
                        case TIFFConstants.COMPRESSION_CCITTFAX3:
                            try {
                                decoder.Decode2D(outBuf, im, 0, height, tiffT4Options);
                            }
                            catch (Exception e) {
                                // let's flip the fill bits and try again...
                                tiffT4Options ^= TIFFConstants.GROUP3OPT_FILLBITS;
                                try {
                                    decoder.Decode2D(outBuf, im, 0, height, tiffT4Options);
                                }
                                catch {
                                    throw e;
                                }
                            }
                            g4.Fax4Encode(outBuf, height);
                            break;
                        case TIFFConstants.COMPRESSION_CCITTFAX4:
                            decoder.DecodeT6(outBuf, im, 0, height, tiffT6Options);
                            g4.Fax4Encode(outBuf, height);
                            break;
                    }
                    rowsLeft -= rowsStrip;
                }
                byte[] g4pic = g4.Close();
                img = Image.GetInstance(w, h, false, Image.CCITTG4, paramsn & Image.CCITT_BLACKIS1, g4pic);
            }
            img.SetDpi(dpiX, dpiY);
            img.XYRatio = XYRatio;
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_ICCPROFILE)) {
                try {
                    TIFFField fd = dir.GetField(TIFFConstants.TIFFTAG_ICCPROFILE);
                    ICC_Profile icc_prof = ICC_Profile.GetInstance(fd.GetAsBytes());
                    if (icc_prof.NumComponents == 1)
                        img.TagICC = icc_prof;
                }
                catch {
                    //empty
                }
            }
            img.OriginalType = Image.ORIGINAL_TIFF;
            if (rotation != 0)
                img.InitialRotation = rotation;
            return img;
        }
        
        protected static Image GetTiffImageColor(TIFFDirectory dir, RandomAccessFileOrArray s) {
            int predictor = 1;
            TIFFLZWDecoder lzwDecoder = null;
            int compression = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_COMPRESSION);
            switch (compression) {
                case TIFFConstants.COMPRESSION_NONE:
                case TIFFConstants.COMPRESSION_LZW:
                case TIFFConstants.COMPRESSION_PACKBITS:
                case TIFFConstants.COMPRESSION_DEFLATE:
                case TIFFConstants.COMPRESSION_ADOBE_DEFLATE:
                case TIFFConstants.COMPRESSION_OJPEG:
                case TIFFConstants.COMPRESSION_JPEG:
                    break;
                default:
                    throw new ArgumentException("The compression " + compression + " is not supported.");
            }
            int photometric = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_PHOTOMETRIC);
            switch (photometric) {
                case TIFFConstants.PHOTOMETRIC_MINISWHITE:
                case TIFFConstants.PHOTOMETRIC_MINISBLACK:
                case TIFFConstants.PHOTOMETRIC_RGB:
                case TIFFConstants.PHOTOMETRIC_SEPARATED:
                case TIFFConstants.PHOTOMETRIC_PALETTE:
                    break;
                default:
                    if (compression != TIFFConstants.COMPRESSION_OJPEG && compression != TIFFConstants.COMPRESSION_JPEG)
                        throw new ArgumentException("The photometric " + photometric + " is not supported.");
                    break;
            }
            float rotation = 0;
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_ORIENTATION)) {
                int rot = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_ORIENTATION);
                if (rot == TIFFConstants.ORIENTATION_BOTRIGHT || rot == TIFFConstants.ORIENTATION_BOTLEFT)
                    rotation = (float)Math.PI;
                else if (rot == TIFFConstants.ORIENTATION_LEFTTOP || rot == TIFFConstants.ORIENTATION_LEFTBOT)
                    rotation = (float)(Math.PI / 2.0);
                else if (rot == TIFFConstants.ORIENTATION_RIGHTTOP || rot == TIFFConstants.ORIENTATION_RIGHTBOT)
                    rotation = -(float)(Math.PI / 2.0);
            }

            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_PLANARCONFIG)
                && dir.GetFieldAsLong(TIFFConstants.TIFFTAG_PLANARCONFIG) == TIFFConstants.PLANARCONFIG_SEPARATE)
                throw new ArgumentException("Planar images are not supported.");
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_EXTRASAMPLES))
                throw new ArgumentException("Extra samples are not supported.");
            int samplePerPixel = 1;
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_SAMPLESPERPIXEL)) // 1,3,4
                samplePerPixel = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_SAMPLESPERPIXEL);
            int bitsPerSample = 1;
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_BITSPERSAMPLE))
                bitsPerSample = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_BITSPERSAMPLE);
            switch (bitsPerSample) {
                case 1:
                case 2:
                case 4:
                case 8:
                    break;
                default:
                    throw new ArgumentException("Bits per sample " + bitsPerSample + " is not supported.");
            }
            Image img = null;

            int h = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_IMAGELENGTH);
            int w = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_IMAGEWIDTH);
            int dpiX = 0;
            int dpiY = 0;
            int resolutionUnit = TIFFConstants.RESUNIT_INCH;
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_RESOLUTIONUNIT))
                resolutionUnit = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_RESOLUTIONUNIT);
            dpiX = GetDpi(dir.GetField(TIFFConstants.TIFFTAG_XRESOLUTION), resolutionUnit);
            dpiY = GetDpi(dir.GetField(TIFFConstants.TIFFTAG_YRESOLUTION), resolutionUnit);
            int fillOrder = 1;
            bool reverse = false;
            TIFFField fillOrderField =  dir.GetField(TIFFConstants.TIFFTAG_FILLORDER);
            if (fillOrderField != null)
                fillOrder = fillOrderField.GetAsInt(0);
            reverse = (fillOrder == TIFFConstants.FILLORDER_LSB2MSB);
            int rowsStrip = h;
            if (dir.IsTagPresent(TIFFConstants.TIFFTAG_ROWSPERSTRIP)) //another hack for broken tiffs
                rowsStrip = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_ROWSPERSTRIP);
            if (rowsStrip <= 0 || rowsStrip > h)
                rowsStrip = h;
            long[] offset = GetArrayLongShort(dir, TIFFConstants.TIFFTAG_STRIPOFFSETS);
            long[] size = GetArrayLongShort(dir, TIFFConstants.TIFFTAG_STRIPBYTECOUNTS);
            if ((size == null || (size.Length == 1 && (size[0] == 0 || size[0] + offset[0] > s.Length))) && h == rowsStrip) { // some TIFF producers are really lousy, so...
                size = new long[]{s.Length - (int)offset[0]};
            }
            if (compression == TIFFConstants.COMPRESSION_LZW) {
                TIFFField predictorField = dir.GetField(TIFFConstants.TIFFTAG_PREDICTOR);
                if (predictorField != null) {
                    predictor = predictorField.GetAsInt(0);
                    if (predictor != 1 && predictor != 2) {
                        throw new Exception("Illegal value for Predictor in TIFF file."); 
                    }
                    if (predictor == 2 && bitsPerSample != 8) {
                        throw new Exception(bitsPerSample + "-bit samples are not supported for Horizontal differencing Predictor.");
                    }
                }
                lzwDecoder = new TIFFLZWDecoder(w, predictor, 
                                                samplePerPixel); 
            }
            int rowsLeft = h;
            MemoryStream stream = null;
            ZDeflaterOutputStream zip = null;
            CCITTG4Encoder g4 = null;
            if (bitsPerSample == 1 && samplePerPixel == 1) {
                g4 = new CCITTG4Encoder(w);
            }
            else {
                stream = new MemoryStream();
                if (compression != TIFFConstants.COMPRESSION_OJPEG && compression != TIFFConstants.COMPRESSION_JPEG)
                    zip = new ZDeflaterOutputStream(stream);
            }
            if (compression == TIFFConstants.COMPRESSION_OJPEG) {

                // Assume that the TIFFTAG_JPEGIFBYTECOUNT tag is optional, since it's obsolete and 
                // is often missing

                if ((!dir.IsTagPresent(TIFFConstants.TIFFTAG_JPEGIFOFFSET))) {
                    throw new IOException("Missing tag(s) for OJPEG compression.");
                }
                int jpegOffset = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_JPEGIFOFFSET);
                int jpegLength = s.Length - jpegOffset;

                if (dir.IsTagPresent(TIFFConstants.TIFFTAG_JPEGIFBYTECOUNT)) {
                    jpegLength = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_JPEGIFBYTECOUNT) +
                        (int)size[0];
                }

                byte[] jpeg = new byte[Math.Min(jpegLength, s.Length - jpegOffset)];

                int posFilePointer = s.FilePointer;
                posFilePointer += jpegOffset;
                s.Seek(posFilePointer);
                s.ReadFully(jpeg);
                img = new Jpeg(jpeg);
            } 
            else if (compression == TIFFConstants.COMPRESSION_JPEG) {
                if (size.Length > 1)
                    throw new IOException("Compression JPEG is only supported with a single strip. This image has " + size.Length + " strips.");
                byte[] jpeg = new byte[(int)size[0]];
                s.Seek(offset[0]);
                s.ReadFully(jpeg);
                img = new Jpeg(jpeg);
            } 
            else {
                for (int k = 0; k < offset.Length; ++k) {
                    byte[] im = new byte[(int)size[k]];
                    s.Seek(offset[k]);
                    s.ReadFully(im);
                    int height = Math.Min(rowsStrip, rowsLeft);
                    byte[] outBuf = null;
                    if (compression != TIFFConstants.COMPRESSION_NONE)
                        outBuf = new byte[(w * bitsPerSample * samplePerPixel + 7) / 8 * height];
                    if (reverse)
                        TIFFFaxDecoder.ReverseBits(im);
                    switch (compression) {
                        case TIFFConstants.COMPRESSION_DEFLATE:
                        case TIFFConstants.COMPRESSION_ADOBE_DEFLATE:
                            Inflate(im, outBuf);
                            break;
                        case TIFFConstants.COMPRESSION_NONE:
                            outBuf = im;
                            break;
                        case TIFFConstants.COMPRESSION_PACKBITS:
                            DecodePackbits(im,  outBuf);
                            break;
                        case TIFFConstants.COMPRESSION_LZW:
                            lzwDecoder.Decode(im, outBuf, height);
                            break;
                    }
                    if (bitsPerSample == 1 && samplePerPixel == 1) {
                        g4.Fax4Encode(outBuf, height);
                    }
                    else {
                        zip.Write(outBuf, 0, outBuf.Length);
                    }
                    rowsLeft -= rowsStrip;
                }
                if (bitsPerSample == 1 && samplePerPixel == 1) {
                    img = Image.GetInstance(w, h, false, Image.CCITTG4, 
                        photometric == TIFFConstants.PHOTOMETRIC_MINISBLACK ? Image.CCITT_BLACKIS1 : 0, g4.Close());
                }
                else {
                    zip.Close();
                    img = Image.GetInstance(w, h, samplePerPixel, bitsPerSample, stream.ToArray());
                    img.Deflated = true;
                }
            }
            img.SetDpi(dpiX, dpiY);
            if (compression != TIFFConstants.COMPRESSION_OJPEG && compression != TIFFConstants.COMPRESSION_JPEG) {
                if (dir.IsTagPresent(TIFFConstants.TIFFTAG_ICCPROFILE)) {
                    try {
                        TIFFField fd = dir.GetField(TIFFConstants.TIFFTAG_ICCPROFILE);
                        ICC_Profile icc_prof = ICC_Profile.GetInstance(fd.GetAsBytes());
                        if (samplePerPixel == icc_prof.NumComponents)
                            img.TagICC = icc_prof;
                    }
                    catch {
                        //empty
                    }
                }
                if (dir.IsTagPresent(TIFFConstants.TIFFTAG_COLORMAP)) {
                    TIFFField fd = dir.GetField(TIFFConstants.TIFFTAG_COLORMAP);
                    char[] rgb = fd.GetAsChars();
                    byte[] palette = new byte[rgb.Length];
                    int gColor = rgb.Length / 3;
                    int bColor = gColor * 2;
                    for (int k = 0; k < gColor; ++k) {
                        palette[k * 3] = (byte)(rgb[k] >> 8);
                        palette[k * 3 + 1] = (byte)(rgb[k + gColor] >> 8);
                        palette[k * 3 + 2] = (byte)(rgb[k + bColor] >> 8);
                    }
                    PdfArray indexed = new PdfArray();
                    indexed.Add(PdfName.INDEXED);
                    indexed.Add(PdfName.DEVICERGB);
                    indexed.Add(new PdfNumber(gColor - 1));
                    indexed.Add(new PdfString(palette));
                    PdfDictionary additional = new PdfDictionary();
                    additional.Put(PdfName.COLORSPACE, indexed);
                    img.Additional = additional;
                }
                img.OriginalType = Image.ORIGINAL_TIFF;
            }
            if (photometric == TIFFConstants.PHOTOMETRIC_MINISWHITE)
                img.Inverted = true;
            if (rotation != 0)
                img.InitialRotation = rotation;
            return img;
        }
        
        static long[] GetArrayLongShort(TIFFDirectory dir, int tag) {
            TIFFField field = dir.GetField(tag);
            if (field == null)
                return null;
            long[] offset;
            if (field.GetType() == TIFFField.TIFF_LONG)
                offset = field.GetAsLongs();
            else { // must be short
                char[] temp = field.GetAsChars();
                offset = new long[temp.Length];
                for (int k = 0; k < temp.Length; ++k)
                    offset[k] = temp[k];
            }
            return offset;
        }
        
        // Uncompress packbits compressed image data.
        public static void DecodePackbits(byte[] data, byte[] dst) {
            int srcCount = 0, dstCount = 0;
            sbyte repeat, b;
            
            try {
                while (dstCount < dst.Length) {
                    b = (sbyte)data[srcCount++];
                    if (b >= 0 && b <= 127) {
                        // literal run packet
                        for (int i=0; i<(b + 1); i++) {
                            dst[dstCount++] = data[srcCount++];
                        }

                    } else if (b <= -1 && b >= -127) {
                        // 2 byte encoded run packet
                        repeat = (sbyte)data[srcCount++];
                        for (int i=0; i<(-b + 1); i++) {
                            dst[dstCount++] = (byte)repeat;
                        }
                    } else {
                        // no-op packet. Do nothing
                        srcCount++;
                    }
                }
            }
            catch {
            }
        }

        public static void Inflate(byte[] deflated, byte[] inflated) {
            byte[] outp = PdfReader.FlateDecode(deflated);
            System.Array.Copy(outp, 0, inflated, 0, Math.Min(outp.Length, inflated.Length));
        }
    }
}
